1. Field of the Invention
The present invention relates to the field of bread dough preparation. The preferred embodiment determines the development status of bread dough in a powered mixer by applying a set of expert rules to qualitative variables determined from the elapsed mixing time and instantaneous power flow to the mixer over time.
2. Description of the Prior Art
Typical white pan bread is composed of the ingredients of water, flour, yeast, sugar, salt and reducing agents. In the commercial preparation of white pan bread, the mixing of the bread dough is the most important processing step. During the mixing, three important processes occur. The first is the blending of the ingredients to achieve a thorough dispersion into a homogeneous mixture. The second process is absorption of the water into the other ingredients, primarily the flour. The third is development of the gluten protein of the flour into a three dimensional matrix so that air is retained during fermentation and so that the bread presents the desired texture and loaf volume.
In commercial bakeries, dough mixing is accomplished in a mixing machine controlled by an experienced and highly skilled baker. The baker judges the characteristics of the dough by smelling, looking and stretching the dough, and by listening to the sound of the mixer's motor. Subjective judgments based on these characteristics are necessary because the attributes of the dough vary from batch to batch. These inconsistencies are due primarily to variations in the flour including its water absorbing capacity and gluten content.
In order to eliminate the need for subjective judgment in the mixing process, one prior art approach is to control the mixing process on the basis of input energy provided to the mixer. For a given mixer and batch size, the amount of delivered energy is directly related to the elapsed mixing time. In this prior art approach, the time set for the mixing cycle is determined by laboratory analysis of the flour protein strength. Unfortunately, the protein strength may drift from batch to batch and dramatic changes can occur when the flour changes to a different source.
Another approach is to integrate the instantaneous input power into a single line curve that reflects the relative consistency of the dough being mixed. This approach, however, only indicates the magnitude of input power which does not provide a correct indication of gluten development.
Other approaches monitor torque on the mixer shaft or rely heavily on laboratory testing before each batch. As those skilled in the art appreciate, none of the prior art techniques provide a reliable real time indication of water absorption and optimal gluten development.